The chemicals, which help remove metals from the body, are potent drugs that carry serious risks, including kidney damage, dehydration and even death, said FDA Medical Officer Dr. Charles Lee. "Chelation can be dangerous and can cause serious harm," Lee said.

The FDA sent letters this week warning eight companies they are in violation of federal law by selling the products. The letters also served to caution parents and others who might be tempted to buy the chelators, which are touted on scores of Web sites and blogs as effective therapies for a wide range of chronic medical problems.

The letters cited several of the companies for selling unapproved, over-the-counter heavy metal screening tests, often taken by consumers who are told they have heavy metal toxicity that can be alleviated by chelators sold by the same company.

The agency has not approved any over-the-counter heavy metal screening tests or chelators, according to the FDA. Physicians usually prescribe approved chelators to treat severe metal poisoning.

Many consumers of chelators are young children with autism, an investigation by the Tribune revealed a year ago. Chelation treatment is popular among parents trying alternative treatments, even though the therapy is dangerous and based on the unproven idea that children with autism have heavy metal poisoning.

Consumers also risk negative health effects if they take chelators instead of treatments proven to be safe and effective.

One of the companies warned by the FDA, Minnesota-based Cardio Renew, touted its oral liquid chelator for angina, pain associated with heart disease that can be a precursor to a heart attack, according to the warning letter sent to the company.

Another company, the New York-based Artery Health Institute, made the following claim, according to the warning letter: "It can reverse atherosclerosis, lower cholesterol levels and blood pressure and help to prevent heart attacks and strokes!"

On its Web site Thursday, the company enticed consumers to "Click here to unclog arteries," which linked to a sale on its Advanced Formula EDTA Oral Chelation. A year's supply was being sold for $299.

"These products are dangerously misleading because they are targeted to patients with serious conditions and limited treatment options," said Deborah Autor, director of the Office of Compliance in the FDA's Center for Drug Evaluation and Research. "The FDA must take a firm stand against companies who prey on the vulnerability of patients seeking hope and relief."

Ron Partain, a pharmacist in Palm Desert, Calif., who said he has been chelating himself for 15 years, said in an interview that the products have a track record of safety. FDA-approved pharmaceuticals cause many more problems and deaths than over-the-counter chelators, he said.

"The FDA is stupid. We are not dangerous," Partain said.

Other recipients of the warning letters are World Health Products, Hormonal Health, Evenbetternow, Maxam Nutraceutics and Maxam Laboratories, Longevity Plus, and Rhonda Henry. None is based in Illinois.

Richard Brooks, a managing member of Hormonal Health, which is based in San Bernardino, Calif., said, "The products are safe and have been around for over a decade."

Henry, a nutritionist based in Nevada, wrote in an e-mail that she did not receive the FDA letter. "If we do … we will certainly co-operate 100% with any and all of their suggestions," Henry wrote.

Other sellers contacted either did not return calls or e-mails or declined comment.

The National Institutes of Health in 2008 halted a controversial government-funded study of chelation and autism before a single child was treated. Other researchers found that rats without lead poisoning showed signs of cognitive damage after being treated with a chelator.

In 2005, a 5-year-old with autism had a heart attack and died while being intravenously chelated in the office of a Pennsylvania physician, according to court records.

And in June, the FDA sent a warning letter to the maker of a supplement called OSR#1 marketed to parents of children with autism. The compound was originally developed as an industrial chelator for wastewater treatment. The product was the subject of a Tribune investigation published in January.

"It's hard to watch the cottage industry of false hope and dangerous therapies that have sprung up around autism," said Dr. Paul Offit, chief of infectious diseases at the Children's Hospital of Philadelphia and author of "Autism's False Prophets: Bad Science, Risky Medicine and the Search for a Cure." "Companies appear to be perfectly willing to prey on parents' growing desperation — a desperation that causes them to do anything, including exposing their children to industrial solvents, to 'cure' autism."

On Thursday morning, Evenbetternow was still selling Kids Chelat on its site ($46.50 a bottle), one of nine products cited in the warning letter. A testimonial cited in the letter was also still on the site: "The Kids Chelat totally changed my autistic son from a hand flapping hyper kid to a sweet mellow angel."

Companies that received the warning letters have 15 working days to respond to the FDA. Failing to correct the violations can result in fines, seizure of products and even criminal prosecution.

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